ROUGH START: Yankees pitcher David Phelps reacts after giving up back-to-back hits in the first inning. Photo: Getty Images

BALTIMORE — “76.’’

As this Yankees season quickly evolves into an embarrassment, The Post is the first to present the Tragic Number.

Any combination of Red Sox wins and Yankees losses totaling 76 will eliminate the Dead Bat Society from the AL East race.

If there was any pretense the Yankees could duplicate the magic of April and May, when they thrived without injured stars, it vanished into the heavy Inner Harbor air Saturday night when the Orioles pummeled the Yankees, 11-3, in front of 46,607 sweaty customers.

The 42-38 Yankees have lost four straight, five of six and 12 of 17. Because the division-leading Red Sox were dumped by the Blue Jays yesterday, the Yankees remained a season-high 5 ½ lengths off the lead. Nevertheless, they are just 2½ games ahead of the last-place Blue Jays.

Orioles lefty Zach Britton threw the first pitch of the game to Brett Gardner at 7:18 p.m. When the first of Chris Davis’ two homers landed in the Orioles bullpen in left-center at 7:36, the O’s had a 4-0 lead and the game essentially was over.

As currently constructed, the Yankees are incapable of scoring more than four runs. Only once in the past six games have the Yankees touched home more than four times — when they scored five against the Rangers this past week and gave up eight.

The Orioles spanked David Phelps (5-5) for nine runs and nine hits (two homers) in 2 ¹/₃ innings. As bad as the right-hander was, it wasn’t his worst outing of the season. On May 29 against the Mets, he recorded one out and gave up five runs (four earned), four hits and walked two.

After watching the anemic Yankees lineup strand three in the top of the first, Phelps gave up three straight singles in front of Davis’ monstrous, opposite-field, three-run homer.

Following a scoreless second, Phelps was tagged for five runs in the third with the key blow being delivered by No. 9 hitter Ryan Flaherty’s three-run homer. Former Yankee Chris Dickerson supplied a two-run single in front of Flaherty’s homer to right.

Manager Joe Girardi removed Phelps from the carnage with one out and called in Ivan Nova to mop up the mess. He added to it by serving up Davis’ second homer, a two-run blow in the sixth that stretched the Orioles’ lead to 11-2. Davis leads the majors with 30 homers.

When Zoilo Almonte’s bases-loaded fly ball to right scored Jayson Nix in the sixth inning with the Yankees’ first run, the crowd — Orioles and Yankees fans alike — responded with a mock cheer.

The second Yankees run of the inning was unearned after a fielding error by Davis at first base.

Thanks to the recent slide, the returns of Derek Jeter, Alex Rodriguez, Curtis Granderson and Francisco Cervelli might not be enough. They are scheduled to come off the disabled list after the All-Star break (July 15-18), but by then the Yankees could be trailing the first-place club by double digits.

If the Yankees can’t reverse this stretch of ineptitude, they certainly will be sellers before the July 31 trade deadline.

And that means Phil Hughes, Joba Chamberlain and Granderson — all free agents at the end of the season — could be dealt.